Abstract: Microstructure of the liquid and solid diffusion bonding region of low carbon steel-H62 brass interlayer-304 stainless steel was examined by means of scanning electron microscope(SEM), energy dispersive X-ray detector(EDX) and X-ray diffractometer(XRD).Metallurgical bonding of carbon steel with stainless steel was achieved through liquid and solid diffusion at carbon steel-brass-stainless steel interfaces.Cu and Zn atoms in the liquid brass diffused through the brass/stainless interface notably, and the formed austenite was surrounded by reticulated brass.On the other hand, solid phase dissolution predominated at carbon steel/brass interface.A kind of island-form iron-rich phase, which contains chromium and nickel, was formed and distributed in brass matrix.And the iron-rich phase remained austenite when cooling to room temperature.